Isabelle Stengers anchors the major stake in Whiteheadian philosophy in the notion of constructivism. In doing so, the relation of this philosophy of becoming — the first anti-substantialist principle of which is stated as `principle of process' — to the ideas of vitalist intuition as the self-expression of the world is announced as eminently problematic. This problematizing opening to Whitehead obliges us to think about the constructivist nature of his concepts because of their irreducibility to the expression of facts of (...) experience since they must necessarily function as a machinic articulation of how things become implied in the `ontological principle' of reason; by the same token, it poses at the heart of the analysis the question of the pragmatic-speculative alterity in Whiteheadian constructivism. (shrink)